From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mark McLoughlin <markmc@redhat.com>
Subject: Re: massive performance drop after a while when using virtio nics
Date: Tue, 09 Sep 2008 11:22:00 +0100
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To: Fabian Deutsch <fabian.deutsch@gmx.de>
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Hi,

On Sat, 2008-08-23 at 21:21 +0200, Fabian Deutsch wrote:
> Hey.
> 
> When running a guest in the following setup, I observ a "massive"
> performance decrease after a couple of gigabytes of transfrerred data.
> 
> other guests keep running fine (no regressions) and nothing unusual is
> observed on the host.

If you do "killall -ALRM qemu-kvm" after the slowdown has occurred, does
it make things speed up again for a while?

If so, the issue is fixed by:

  http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=ba661292a2bc6ddd305a212b0526e5dc22195fe7

It also got applied in 2.6.26.3 and 2.6.25.16.

Cheers,
Mark.